Wellcome Sanger Institute researchers are studying Klebsiella pneumoniae bacterial pneumonia. This bacterium is the main cause of pneumonia contracted in hospitals or by fragile people. More and more strains of this bacteria are resistant to more and more antibiotics.

Researchers want to discover which genes allow the bacteria to attach to host cells, as well as those that allow it to escape the immune system.

For this purpose they have created mutant strains of the bacterium from an original strain collected in a hospital. They then injected these mutant strains into living organisms to see which ones were capable of triggering an infection.

For this study, the researchers turned to caterpillars. This animal lacks a central nervous system and pain receptors, has an immune system comparable to ours and is increasingly used in microbiological research.

The researchers used 200 caterpillars and were able to identify genes already known to be necessary for infection, which showed the validity of the model, but also new genes that had never been linked to infection in any bacterial strain.

These discoveries open new avenues in the search for anti-infectious therapies.

This study received a 3Rs award from the National Center for the British Refining & Reduction of Animals in Research.